php preg split a string

Question

I have a numeric string and I'd need to split it in groups of 2 starting from right, but not more than three groups.

To understand, the 3 groups are 'copper', 'silver' and 'gold' and the starting value is a synthetic money amount. For example:

10 -> 10 copper

1010 -> 10 silver and 10 copper

102030 -> 10 gold, 20 silver and 30 copper

1234567891010 -> 123456789 gold, 10 silver and 10 copper

how to do it in php?

preg_split($pattern, $subject) but I don't know what pattern to write... :( — the_nutria, Dec 24 '12 at 15:00
As @Michael said I'd do math instead of regex. Save it all in copper and then transform it into gold, silver and copper. — Javier Diaz, Dec 24 '12 at 15:06

score 5 · Accepted Answer · edited Dec 24 '12 at 15:25

5

I would just convert the String to an int like here and then do some arithmetical operations.

Let x be the number

r1 = x % 10000;
gold = x / 10000;
copper = r1 % 100;
silver = r1 / 100;

so you have all your information.

Where % means modulo

edited Dec 24 '12 at 15:25

Jelmer

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answered Dec 24 '12 at 15:06

Alex VII

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oh yes that is much simpler than splitting the string! I didn't get that % thing but I've used a floor() to truncate decimal values. thank you – the_nutria Dec 24 '12 at 15:18
% means modulo, so for example 5 % 2 is 3, so 3 ist the rest if you devide 5 by 2. Another example is: 1002 % 10 is 2, so 1002 = 100 * 10 + 2 – Alex VII Dec 24 '12 at 15:21
@the_nutria Here are the docs: http://php.net/manual/en/language.operators.arithmetic.php – Jelmer Dec 24 '12 at 15:23
@the_nutria % is the modulo operator. Basically, you're dividing something by another number, and instead of returning the result, you return the remainder. ie 100/13 = 7.69, so 100 % 13 would return 100 - (13 * 7) = 100 - 91 = 9 – Michael Dec 24 '12 at 15:23

score 0 · Answer 2 · answered Dec 24 '12 at 15:15

Using a regular expression:

$items = array('12', '1234', '123456', '1234567891234');

foreach ($items as $item)
{
    echo $item;

    preg_match('/^(?:(?<gold>\d*)(?<silver>\d\d))?(?<copper>\d\d)$/', $item, $result);

    foreach ($result as $key => $value)
    {
        if (is_int($key))
        {
            unset($result[$key]);
        }
    }
    var_dump($result);
}

php preg split a string

2 Answers2